The field of the invention relates to flow control devices and more specifically the fields of hydraulic and hydrologic engineering.
Detention ponds are required in most municipalities when a previously undisturbed area is developed resulting in a higher peak runoff discharge. The most common reason for a higher peak runoff is because of an increase in impervious area which decreases the area that water is able to percolate into the ground.
Current methods of restricting the post-development peak discharge to equal predevelopment discharge levels include using a stationary culvert, weir or a combination of the two. The use of these devices only allows the peak discharge to occur when the water level in the detention pond is at its peak height which usually occurs for a relatively short amount of time.
The flow control gate for detention pond allows the detention pond to discharge runoff at the peak pre-development flow rate as soon as the peak pre-development flow enters the detention pond. The gate is lowered and raised by means of a float monitored by a curved track so that the discharge always meets historical levels.
The orifice equation was the main equation used in the development of the flow control gate for detention pond. A widely accepted form of the orifice equation is Q=C*A*sqrt(2*g*h) where Q is the flow, C is the orifice coefficient, A is the area of the opening, g is the rate of gravitational acceleration and h is head. The orifice coefficient and gravitational acceleration are kept constant when the flow control gate for detention pond is operational. The head changes as the water raises and lowers in the detention pond which moves a float that controls the gate area so that the result is a constant flow no matter what the water level in the detention pond is. Other devices rely on electricity or more mechanisms that can easily be damaged and require much maintenance. By using the curved track for the flow control gate for detention pond there is no electricity required and we reduce the number of moving parts resulting in less chance of mechanical failure.